Flexible sign assemblies are desirable for several reasons, including relatively low cost and relatively easy transportation and installation. Typically, such flexible sign assemblies include the flexible sign itself, a frame to support the flexible sign, and a "tensioning system" for securing the flexible sign to the frame. The tensioning system has been the focus of previous patents, including U.S. Pat. No. 4,955,928 to Tanner.
The device disclosed in Tanner has a frame with a tensioning edge over which a flexible sign membrane is tensioned. The sign membrane is wrapped around a mounting bar, which in turn, is snapped into a series of small connector components. Each of the connector components includes a plurality of sawtooth ridges that interengage with mating sawtooth ridges on the frame. The interengaging ridges allow movement of the connector components in a first direction to tighten the sign membrane, but prevent movement of the connector components in a second direction in order to maintain tension in the sign membrane. A notch is formed in the frame beyond the mating sawtooth ridges in the first direction to provide means for using a compressing tool to tension the sign membrane.
One problem with the device disclosed in Tanner is that a substantial portion of the sign membrane is wrapped around each mounting bar, making it difficult to make finite tension adjustments. Also, the fact that a series of connector components are snapped onto each mounting bar further complicates the installation process. If a relatively minor adjustment is required, it is necessary to remove all of the connector components by unsnapping them from the mounting bar. Additionally, the long mounting bars limit applications of the Tanner device to sign configurations that are regularly shaped with relatively long and straight edges. Yet another disadvantage of the Tanner device is that a special compressing tool is required in order to significantly tension the sign membrane. The present invention provides a reliable, easy to use tensioning system that overcomes the shortcomings of other available devices, such as that disclosed in Tanner.